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United States Patent | 5,345,860 |
Bowell | September 13, 1994 |
A piston for use in a hydraulic cylinder which is subject to sudden and extremely high shock load pressures and high temperature operating conditions is provided with a plurality of interlocking axially-spaced circumferential grooves. A band of a heat-formable fluoropolymer is snapped over a retaining ring integral with the piston and the piston is then moved axially through a heated hot-forming cylinder, causing the washer to conform to the cylindrical shape of the piston. At least one circumferential has a side wall which is undercut relative to its cylindrical surface to provide a locking angle. A method of washer preheating prior to hot-forming the band results in better flow of the fluoropolymer toward the undercut side wall. The method of preheating also produces a band skirt with a relatively sharply-defined sealing edge.
Inventors: | Bowell; Richard A. (Huber Heights, OH) |
Assignee: | Tri Dayton, Inc. (Troy, OH) |
Appl. No.: | 086054 |
Filed: | July 6, 1993 |
Current U.S. Class: | 92/192; 29/888.047; 92/240; 92/250; 277/453; 277/923 |
Intern'l Class: | F16J 009/00; B23P 015/10; F02F 003/00 |
Field of Search: | 92/192,240,250,249,254 277/170,171,172 29/888.04,888.047,888.049 |
1584470 | May., 1926 | Quintenz | 277/172. |
1797781 | Mar., 1931 | McCaughey | 92/254. |
2176281 | Oct., 1939 | Stillwagon | 92/254. |
2216577 | Oct., 1940 | Stillwagon | 92/254. |
2779646 | Jan., 1957 | Creed | 277/172. |
3072071 | Jan., 1963 | Stroud | 92/254. |
3212411 | Oct., 1965 | Storms. | |
3237953 | Mar., 1966 | Lucas | 277/172. |
Foreign Patent Documents | |||
1503463 | Aug., 1970 | DE | 92/249. |